Quantum Decoherence and Entanglement in Continuous Variable Open Systems

by Prof. Aurelian Isar (Department of Theoretical Physics, National Institute of Physics and Nuclear Engineering, Bucharest-Magurele, Romania)

Sunday 20 Nov 2011, 11:00 → 12:00 Europe/Belgrade

Room 3 (Faculty of Science-Institute of Physics, Kragujevac (Radoja Domanovica 12))

In the framework of the theory of open systems based on completely positive quantum dynamical semigroups, we determine the degree of quantum decoherence of a harmonic oscillator interacting with a thermal bath. We calculate the decoherence time and show that it has the same scale as the time after which the statistical fluctuations become comparable with the quantum fluctuations. The transition from quantum to classical behavior of the considered system is analyzed.
For a systems consisting of two independent harmonic oscillators interacting with a thermal bath we describe the time evolution of the continuous-variable entanglement in terms of the covariance matrix of quantum states of the considered system for Gaussian input states.